Small angle X-ray scattering from block copolymer/homopolymer mixtures

✍ Scribed by J.G. Connell; R.W. Richards

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 485 KB
• Volume: 29
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(93)90101-k

✦ Synopsis

The salient points of the application of the random phase approximation to block copolymers and their mixtures with homopolymers are set out. The predictions with regard to the form of the small angle X-ray scattering pattern are noted and experiments on mixtures of a styren~isoprene block copolymer (mole fraction of styrene = 0.5) mixed with polyisoprene are reported. Values of the Flory-Huggins interaction parameter, its temperature dependence and the spinodal temperatures of the pure block copolymer and two of its mixtures with the homopolymer are reported. The partial phase diagram obtained is compared with that predicted by theory. There is excess scattering intensity at very low Q which is not due to the assumption of incompressibility since it is not reproduced by current theories where this condition is relaxed.